Discussion:
In the present study we determined the epidemiological features of extremity traumatic amputation in our region generally. To the best of our knowledge previous studies considered the special characteristics of traumatic amputation in special situations. So comparison of the results of our study with previous studies seems to be not reasonable in some aspects.

The sex ratio in our study (male>80%) is similar to other studies (4-6).

Traumatic amputation was seen with increasing frequency from the second to fifth decades of life. Liang et al (5) reported young male manufacturing workers were at high risk of occupational amputation of upper extremities. But Timothy et al (2) reported increasing risk of amputation on those older than 85 years. Conn et al (7) observed greatest risk of non-work related finger amputation in young children and older adults in the United States. 

More than 60% of our cases sustained occupational related injury with high frequency in industrial and agricultural works. This finding is compatible with the results of Boyle et al (8), Onuba (9) and Stanbury et al (10) researches. We found in the non-occupational group motor vehicle accident was the most common cause (24.5%). This finding is consistent with the result of Livingston et al (1) study.

With regard to temporal distribution, we observed traumatic amputation was more frequent in the spring and autumn and in the May and September. Spring and autumn are planting and harvesting time and May and September is the peak of planting and harvesting activities respectively in our region. It was reported there are common patterns of traumatic amputations in children based on the mechanism of injury, the season and the age of  the child (11). A study from Hansen (12) showed highest incidence of major injury due to agricultural machinery during spring planting (May through June )  and fall harvesting (September through October ) time .

In our series upper extremity was involved in 88.5% of cases which is higher than the finding of Timothy et al (2). Hansen and Carstensen (13) demonstrated in agricultural machinery injury, upper extremity was the most common site of injury.

The hand and its distal part (finger) sustained the most common traumatic amputation in our cases. Timothy et al (2) research resulted that half of all trauma – related amputation occurred in the upper extremity and three quarter of all upper extremity traumatic amputation occurred in the lower part of upper extremity (finger) Regarding to involvement of  individual finger , in the present study  one finger was  amputated  mostly and  thumb plus finger the least .Triziolou et al (14) showed hand injury of childrens with  agricultural machinery were most commonly associated with injury of third digit and the thumb was the least. We found distal phalanx was amputated most commonly. Doraiswamy and Baing (15) research resulted in terminal phalanx was the most common injured (not amputated) part in children.

It is concluded that extremity traumatic  amputation was more prevalent in young male , industrial and agricultural workers , motor vehicle accidents, spring and autumn  seasons and upper extremity especially  its distal part. With regard to these epidemiological characteristics accordingly appropriate precaution measures may decline the incidence or decrease the severity of extremity traumatic amputation.  

Acknowledgement:
We wish to acknowledge the personnel of records sections of Shahid Beheshti and Shahid Yahyanejad Hospitals for their help in data collection.

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